Novolipetsk Metallurgical Plant, Lipetsk, Russia
E. A. Milokhin, Expert on Ore-thermal Processes and Briquetting, Directorate for the Development of New Process Technologies, e-mail: milohin_ea@nlmk.com
A. S. Batishcheva, Engineer, Directorate for the Development of New Process Technologies, e-mail: batischeva_as@nlmk.com

Novotroitsk branch of the National University of Science and Technology “MISIS”, Novotroitsk, Russia
A. N. Shapovalov, Cand. Eng., Associate Prof., Dept. of Metallurgical Technologies and Equipment, e-mail: alshapo@misis.ru

It is shown that under the conditions of operating production the decisive influence on the results of pelletizing has the moisture of sinter charge. The optimum moisture level is selected experimentally depending on the sinter charge composition, the components of which have different clumpability. In order to obtain good pelletizing results (the granulometric composition of the charge and the granules strength), the sinter charge must contain a variety of fractions with a certain number of fine (colloidal) classes. The results of laboratory experiments to study the influence of the size of the concentrate on the results of pelletizing and sintering in the charge conditions of Novolipetsk Steel are pre-sented. It was found that the use of iron ore concentrate with a higher degree of grinding worsens the results of pelletizing, sintering indicators and sinter quality. The results obtained are explained mainly by the deterioration of the clumpability of the sintering charge with the experimental concentrate, which is reflected in the results of pelletizing and granules strength (both in the raw state and in the sintering process). Reducing the granules strength leads to a decrease in gas permeability of the sintered layer, sintering speed and productivity, as well as worsens the thermal conditions of sintering and the sinter strength.

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